From patchwork Mon Jan 9 14:03:18 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marek Szyprowski X-Patchwork-Id: 9504837 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 7598A60757 for ; Mon, 9 Jan 2017 14:05:03 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 67278284E4 for ; Mon, 9 Jan 2017 14:05:03 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 5ADDD284E8; Mon, 9 Jan 2017 14:05:03 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4F5F7284E4 for ; Mon, 9 Jan 2017 14:05:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S967917AbdAIOEw (ORCPT ); Mon, 9 Jan 2017 09:04:52 -0500 Received: from mailout3.w1.samsung.com ([210.118.77.13]:23234 "EHLO mailout3.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S942379AbdAIODc (ORCPT ); Mon, 9 Jan 2017 09:03:32 -0500 Received: from eucas1p1.samsung.com (unknown [182.198.249.206]) by mailout3.w1.samsung.com (Oracle Communications Messaging Server 7.0.5.31.0 64bit (built May 5 2014)) with ESMTP id <0OJI00JMBN1S3670@mailout3.w1.samsung.com>; Mon, 09 Jan 2017 14:03:28 +0000 (GMT) Received: from eusmges4.samsung.com (unknown [203.254.199.244]) by eucas1p2.samsung.com (KnoxPortal) with ESMTP id 20170109140328eucas1p23bf84a8dbb81481454f6e7841ea17ad4~YH2fZwPsD1476214762eucas1p2S; Mon, 9 Jan 2017 14:03:28 +0000 (GMT) Received: from eucas1p1.samsung.com ( [182.198.249.206]) by eusmges4.samsung.com (EUCPMTA) with SMTP id 8D.A6.28517.F2893785; Mon, 9 Jan 2017 14:03:27 +0000 (GMT) Received: from eusmgms2.samsung.com (unknown [182.198.249.180]) by eucas1p2.samsung.com (KnoxPortal) with ESMTP id 20170109140327eucas1p20df21c98a5744003cd2687162f35ec10~YH2eqWdaZ1631216312eucas1p2I; Mon, 9 Jan 2017 14:03:27 +0000 (GMT) X-AuditID: cbfec7f4-f79716d000006f65-ea-5873982f13ee Received: from eusync3.samsung.com ( [203.254.199.213]) by eusmgms2.samsung.com (EUCPMTA) with SMTP id D1.BC.10233.72893785; Mon, 9 Jan 2017 14:03:19 +0000 (GMT) Received: from AMDC2765.digital.local ([106.116.147.25]) by eusync3.samsung.com (Oracle Communications Messaging Server 7.0.5.31.0 64bit (built May 5 2014)) with ESMTPA id <0OJI005JBN1K8V20@eusync3.samsung.com>; Mon, 09 Jan 2017 14:03:27 +0000 (GMT) From: Marek Szyprowski To: linux-samsung-soc@vger.kernel.org, dmaengine@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-pm@vger.kernel.org Cc: Marek Szyprowski , Krzysztof Kozlowski , Bartlomiej Zolnierkiewicz , Vinod Koul , Ulf Hansson , "Rafael J. Wysocki" , Inki Dae Subject: [PATCH v2 4/4] dmaengine: pl330: Don't require irq-safe runtime PM Date: Mon, 09 Jan 2017 15:03:18 +0100 Message-id: <1483970598-6191-5-git-send-email-m.szyprowski@samsung.com> X-Mailer: git-send-email 1.9.1 In-reply-to: <1483970598-6191-1-git-send-email-m.szyprowski@samsung.com> X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFnrCIsWRmVeSWpSXmKPExsWy7djPc7r6M4ojDF5tM7bYOGM9q8XqqX9Z LSbdn8Bicf78BnaLTY+vsVp87j3CaDHj/D4mi7VH7rJbnDl9idXi+Npwi5d9+1kcuD0W73nJ 5LFpVSebx51re9g8Ni+p99hytZ3Fo2/LKkaPz5vkAtijuGxSUnMyy1KL9O0SuDLuHt/FUrA6 pmLXvyXsDYybfLoYOTkkBEwk2vddYYKwxSQu3FvPBmILCSxllLi5IryLkQvI/swoMWHxLUaY hg8rmhghEssYJT58ms0G4TQwScyYPZcVpIpNwFCi620XWEJEoIlR4u385WAtzAJLmSQ2t79k B6kSFvCWWHvyPthCFgFViYnNG1i6GDk4eAXcJZa8kIdYJydx8thksKGcAh4Sn1fMZAGZIyEw j11i88YHzCD1EgKyEpsOMEPUu0gcO7oX6h9hiVfHt7BD2DISlyd3s0DY/YwSTa3aEPYMRolz b3khbGuJw8cvgu1iFuCTmLRtOtR4XomONiGIEg+JW8+WM0GEHSV+TfOF+H02o8Tcl/fZJzDK LGBkWMUoklpanJueWmyiV5yYW1yal66XnJ+7iREY96f/Hf+yg3HxMatDjAIcjEo8vBETiiOE WBPLiitzDzFKcDArifDemAIU4k1JrKxKLcqPLyrNSS0+xCjNwaIkzrtnwZVwIYH0xJLU7NTU gtQimCwTB6dUA2Po1y9/Jt/791uxc/rvmrZpMZ+erYheG7zeSMT/g1/IBLViqaV9aoq3XLy2 HFWzKYiy8ZH48rf8cdmz+A92Kjw9q5xnReuX+12bsirRiGGOWKCF0YftV4971rnx3NC9WVN1 ek+Wy691W+Lu3eLR0nrln30/LPOJ5+mM/S9sjS579VcnVxyfl6PEUpyRaKjFXFScCACrSZzx 9wIAAA== X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFmplkeLIzCtJLcpLzFFi42I5/e/4VV31GcURBh/vcltsnLGe1WL11L+s FpPuT2CxOH9+A7vFpsfXWC0+9x5htJhxfh+Txdojd9ktzpy+xGpxfG24xcu+/SwO3B6L97xk 8ti0qpPN4861PWwem5fUe2y52s7i0bdlFaPH501yAexRbjYZqYkpqUUKqXnJ+SmZeem2SqEh broWSgp5ibmptkoRur4hQUoKZYk5pUCekQEacHAOcA9W0rdLcMu4e3wXS8HqmIpd/5awNzBu 8uli5OSQEDCR+LCiiRHCFpO4cG89WxcjF4eQwBJGiTd7zjJBOE1MEpcX/WYGqWITMJToetvF BmKLCDQxShz85QFSxCywnEliy/QL7CAJYQFvibUn74MVsQioSkxs3sDSxcjBwSvgLrHkhTzE NjmJk8cms4LYnAIeEp9XzGQBsYWASjrePmefwMi7gJFhFaNIamlxbnpusZFecWJucWleul5y fu4mRmAUbDv2c8sOxq53wYcYBTgYlXh4IyYURwixJpYVV+YeYpTgYFYS4b0xBSjEm5JYWZVa lB9fVJqTWnyI0RToponMUqLJ+cAIzSuJNzQxNLc0NDK2sDA3MlIS55364Uq4kEB6Yklqdmpq QWoRTB8TB6dUA2ODUkdCX3Ad5+y4Q5seHrscO2tSZLIRg+nMDUJmiyoqhdbteOdqtGRu6J+0 6T3Pjmgp5PTt+Rjim9UWKRcdc0r5t5WlQcuSgBNSB49PWburMcggIK45TiWCL5vvxvRZZjkN wty5Ivwadn+efDb3uvXJ0pivqePykTcRpvezxZWm5l++4JWvpsRSnJFoqMVcVJwIAE4DXGKY AgAA X-MTR: 20000000000000000@CPGS X-CMS-MailID: 20170109140327eucas1p20df21c98a5744003cd2687162f35ec10 X-Msg-Generator: CA X-Sender-IP: 182.198.249.180 X-Local-Sender: =?UTF-8?B?TWFyZWsgU3p5cHJvd3NraRtTUlBPTC1LZXJuZWwgKFRQKRs=?= =?UTF-8?B?7IK87ISx7KCE7J6QG1NlbmlvciBTb2Z0d2FyZSBFbmdpbmVlcg==?= X-Global-Sender: =?UTF-8?B?TWFyZWsgU3p5cHJvd3NraRtTUlBPTC1LZXJuZWwgKFRQKRtT?= =?UTF-8?B?YW1zdW5nIEVsZWN0cm9uaWNzG1NlbmlvciBTb2Z0d2FyZSBFbmdpbmVlcg==?= X-Sender-Code: =?UTF-8?B?QzEwG0VIURtDMTBDRDAyQ0QwMjczOTI=?= CMS-TYPE: 201P X-HopCount: 7 X-CMS-RootMailID: 20170109140327eucas1p20df21c98a5744003cd2687162f35ec10 X-RootMTR: 20170109140327eucas1p20df21c98a5744003cd2687162f35ec10 References: <1483970598-6191-1-git-send-email-m.szyprowski@samsung.com> Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This patch replaces irq-safe runtime PM with non-irq-safe version based on the new approach. Existing, irq-safe runtime PM implementation for PL330 was not bringing much benefits of its own - only clocks were enabled/disabled. Till now non-irq-safe runtime PM implementation was only possible by calling pm_runtime_get/put functions from alloc/free_chan_resources. All other DMA engine API functions cannot be called from a context, which permits sleeping. Such implementation, in practice would result in keeping DMA controller's device active almost all the time, because most of the slave device drivers (DMA engine clients) acquire DMA channel in their probe() function and released it during driver removal. This patch provides a new, different approach. It is based on an observation that there can be only one slave device using each DMA channel. PL330 hardware always has dedicated channels for each peripheral device. Using recently introduced device dependencies (links) infrastructure one can ensure proper runtime PM state of PL330 DMA controller basing on the runtime PM state of the slave device. In this approach in pl330_alloc_chan_resources() function a new dependency is being created between PL330 DMA controller device (as a supplier) and given slave device (as a consumer). This way PL330 DMA controller device runtime active counter is increased when the slave device is resumed and decreased the same time when given slave device is put to suspend. This way it has been ensured to keep PL330 DMA controller runtime active if there is an active used of any of its DMA channels. Slave device pointer is initially stored in per-channel data in of_dma_xlate callback. This is similar to what has been already implemented in Exynos IOMMU driver in commit 2f5f44f205cc95 ("iommu/exynos: Use device dependency links to control runtime pm"). If slave device doesn't implement runtime PM or keeps device runtime active all the time, then PL330 DMA controller will be runtime active all the time when channel is being allocated. The goal is however to have runtime PM added to all devices in the system, because it lets respective power domains to be turned off, what gives the best results in terms of power saving. If one requests memory-to-memory channel, runtime active counter is increased unconditionally. This might be a drawback of this approach, but PL330 is not really used for memory-to-memory operations due to poor performance in such operations compared to the CPU. Introducing non-irq-safe runtime power management finally allows to turn off audio power domain on Exynos5 SoCs. Removal of irq-safe runtime PM is based on the revert of the following commits: 1. "dmaengine: pl330: fix runtime pm support" commit 5c9e6c2b2ba3ec3a442e2fb5b4286498f8b4dcb7 2. "dmaengine: pl330: Fix hang on dmaengine_terminate_all on certain boards" commit 81cc6edc08705ac0146fe6ac14a0982a31ce6f3d 3. "ARM: 8202/1: dmaengine: pl330: Add runtime Power Management support v12" commit ae43b3289186480f81c78bb63d788a85a3631f47 Signed-off-by: Marek Szyprowski Reviewed-by: Krzysztof Kozlowski --- drivers/dma/pl330.c | 124 ++++++++++++++++++++++++++-------------------------- 1 file changed, 61 insertions(+), 63 deletions(-) diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c index 9c72f535739c..2cffbb44b09e 100644 --- a/drivers/dma/pl330.c +++ b/drivers/dma/pl330.c @@ -268,9 +268,6 @@ enum pl330_byteswap { #define NR_DEFAULT_DESC 16 -/* Delay for runtime PM autosuspend, ms */ -#define PL330_AUTOSUSPEND_DELAY 20 - /* Populated by the PL330 core driver for DMA API driver's info */ struct pl330_config { u32 periph_id; @@ -449,8 +446,8 @@ struct dma_pl330_chan { bool cyclic; /* for runtime pm tracking */ - bool active; struct device *slave; + struct device_link *slave_link; }; struct pl330_dmac { @@ -2016,7 +2013,6 @@ static void pl330_tasklet(unsigned long data) struct dma_pl330_chan *pch = (struct dma_pl330_chan *)data; struct dma_pl330_desc *desc, *_dt; unsigned long flags; - bool power_down = false; spin_lock_irqsave(&pch->lock, flags); @@ -2031,18 +2027,10 @@ static void pl330_tasklet(unsigned long data) /* Try to submit a req imm. next to the last completed cookie */ fill_queue(pch); - if (list_empty(&pch->work_list)) { - spin_lock(&pch->thread->dmac->lock); - _stop(pch->thread); - spin_unlock(&pch->thread->dmac->lock); - power_down = true; - pch->active = false; - } else { - /* Make sure the PL330 Channel thread is active */ - spin_lock(&pch->thread->dmac->lock); - _start(pch->thread); - spin_unlock(&pch->thread->dmac->lock); - } + /* Make sure the PL330 Channel thread is active */ + spin_lock(&pch->thread->dmac->lock); + _start(pch->thread); + spin_unlock(&pch->thread->dmac->lock); while (!list_empty(&pch->completed_list)) { struct dmaengine_desc_callback cb; @@ -2055,13 +2043,6 @@ static void pl330_tasklet(unsigned long data) if (pch->cyclic) { desc->status = PREP; list_move_tail(&desc->node, &pch->work_list); - if (power_down) { - pch->active = true; - spin_lock(&pch->thread->dmac->lock); - _start(pch->thread); - spin_unlock(&pch->thread->dmac->lock); - power_down = false; - } } else { desc->status = FREE; list_move_tail(&desc->node, &pch->dmac->desc_pool); @@ -2076,12 +2057,6 @@ static void pl330_tasklet(unsigned long data) } } spin_unlock_irqrestore(&pch->lock, flags); - - /* If work list empty, power down */ - if (power_down) { - pm_runtime_mark_last_busy(pch->dmac->ddma.dev); - pm_runtime_put_autosuspend(pch->dmac->ddma.dev); - } } bool pl330_filter(struct dma_chan *chan, void *param) @@ -2125,11 +2100,52 @@ static struct dma_chan *of_dma_pl330_xlate(struct of_phandle_args *dma_spec, return dma_get_slave_channel(&pl330->peripherals[chan_id].chan); } +static int pl330_add_slave_link(struct pl330_dmac *pl330, + struct dma_pl330_chan *pch) +{ + struct device_link *link; + int i; + + if (pch->slave_link) + return 0; + + link = device_link_add(pch->slave, pl330->ddma.dev, + DL_FLAG_PM_RUNTIME | DL_FLAG_RPM_ACTIVE); + if (!link) + return -ENODEV; + + for (i = 0; i < pl330->num_peripherals; i++) + if (pl330->peripherals[i].slave == pch->slave) + pl330->peripherals[i].slave_link = link; + return 0; +} + +static void pl330_del_slave_link(struct pl330_dmac *pl330, + struct dma_pl330_chan *pch) +{ + struct device_link *link = pch->slave_link; + int i, count = 0; + + for (i = 0; i < pl330->num_peripherals; i++) + if (pl330->peripherals[i].slave == pch->slave && + pl330->peripherals[i].thread) + count++; + + if (count > 0) + return; + + device_link_del(link); + for (i = 0; i < pl330->num_peripherals; i++) + if (pl330->peripherals[i].slave == pch->slave) + pch->slave_link = NULL; +} + static int pl330_alloc_chan_resources(struct dma_chan *chan) { struct dma_pl330_chan *pch = to_pchan(chan); struct pl330_dmac *pl330 = pch->dmac; unsigned long flags; + int ret = 0; spin_lock_irqsave(&pch->lock, flags); @@ -2146,6 +2162,14 @@ static int pl330_alloc_chan_resources(struct dma_chan *chan) spin_unlock_irqrestore(&pch->lock, flags); + if (pch->slave) + ret = pl330_add_slave_link(pl330, pch); + else + ret = pm_runtime_get_sync(pl330->ddma.dev); + + if (ret < 0) + return ret; + return 1; } @@ -2180,9 +2204,7 @@ static int pl330_terminate_all(struct dma_chan *chan) unsigned long flags; struct pl330_dmac *pl330 = pch->dmac; LIST_HEAD(list); - bool power_down = false; - pm_runtime_get_sync(pl330->ddma.dev); spin_lock_irqsave(&pch->lock, flags); spin_lock(&pl330->lock); _stop(pch->thread); @@ -2191,8 +2213,6 @@ static int pl330_terminate_all(struct dma_chan *chan) pch->thread->req[0].desc = NULL; pch->thread->req[1].desc = NULL; pch->thread->req_running = -1; - power_down = pch->active; - pch->active = false; /* Mark all desc done */ list_for_each_entry(desc, &pch->submitted_list, node) { @@ -2209,10 +2229,6 @@ static int pl330_terminate_all(struct dma_chan *chan) list_splice_tail_init(&pch->work_list, &pl330->desc_pool); list_splice_tail_init(&pch->completed_list, &pl330->desc_pool); spin_unlock_irqrestore(&pch->lock, flags); - pm_runtime_mark_last_busy(pl330->ddma.dev); - if (power_down) - pm_runtime_put_autosuspend(pl330->ddma.dev); - pm_runtime_put_autosuspend(pl330->ddma.dev); return 0; } @@ -2230,7 +2246,6 @@ static int pl330_pause(struct dma_chan *chan) struct pl330_dmac *pl330 = pch->dmac; unsigned long flags; - pm_runtime_get_sync(pl330->ddma.dev); spin_lock_irqsave(&pch->lock, flags); spin_lock(&pl330->lock); @@ -2238,8 +2253,6 @@ static int pl330_pause(struct dma_chan *chan) spin_unlock(&pl330->lock); spin_unlock_irqrestore(&pch->lock, flags); - pm_runtime_mark_last_busy(pl330->ddma.dev); - pm_runtime_put_autosuspend(pl330->ddma.dev); return 0; } @@ -2247,11 +2260,11 @@ static int pl330_pause(struct dma_chan *chan) static void pl330_free_chan_resources(struct dma_chan *chan) { struct dma_pl330_chan *pch = to_pchan(chan); + struct pl330_dmac *pl330 = pch->dmac; unsigned long flags; tasklet_kill(&pch->task); - pm_runtime_get_sync(pch->dmac->ddma.dev); spin_lock_irqsave(&pch->lock, flags); pl330_release_channel(pch->thread); @@ -2261,19 +2274,20 @@ static void pl330_free_chan_resources(struct dma_chan *chan) list_splice_tail_init(&pch->work_list, &pch->dmac->desc_pool); spin_unlock_irqrestore(&pch->lock, flags); - pm_runtime_mark_last_busy(pch->dmac->ddma.dev); - pm_runtime_put_autosuspend(pch->dmac->ddma.dev); + + if (pch->slave) + pl330_del_slave_link(pl330, pch); + else + pm_runtime_put(pl330->ddma.dev); } static int pl330_get_current_xferred_count(struct dma_pl330_chan *pch, struct dma_pl330_desc *desc) { struct pl330_thread *thrd = pch->thread; - struct pl330_dmac *pl330 = pch->dmac; void __iomem *regs = thrd->dmac->base; u32 val, addr; - pm_runtime_get_sync(pl330->ddma.dev); val = addr = 0; if (desc->rqcfg.src_inc) { val = readl(regs + SA(thrd->id)); @@ -2282,8 +2296,6 @@ static int pl330_get_current_xferred_count(struct dma_pl330_chan *pch, val = readl(regs + DA(thrd->id)); addr = desc->px.dst_addr; } - pm_runtime_mark_last_busy(pch->dmac->ddma.dev); - pm_runtime_put_autosuspend(pl330->ddma.dev); /* If DMAMOV hasn't finished yet, SAR/DAR can be zero */ if (!val) @@ -2369,16 +2381,6 @@ static void pl330_issue_pending(struct dma_chan *chan) unsigned long flags; spin_lock_irqsave(&pch->lock, flags); - if (list_empty(&pch->work_list)) { - /* - * Warn on nothing pending. Empty submitted_list may - * break our pm_runtime usage counter as it is - * updated on work_list emptiness status. - */ - WARN_ON(list_empty(&pch->submitted_list)); - pch->active = true; - pm_runtime_get_sync(pch->dmac->ddma.dev); - } list_splice_tail_init(&pch->submitted_list, &pch->work_list); spin_unlock_irqrestore(&pch->lock, flags); @@ -2996,11 +2998,7 @@ static int __maybe_unused pl330_resume(struct device *dev) pcfg->data_buf_dep, pcfg->data_bus_width / 8, pcfg->num_chan, pcfg->num_peri, pcfg->num_events); - pm_runtime_irq_safe(&adev->dev); - pm_runtime_use_autosuspend(&adev->dev); - pm_runtime_set_autosuspend_delay(&adev->dev, PL330_AUTOSUSPEND_DELAY); - pm_runtime_mark_last_busy(&adev->dev); - pm_runtime_put_autosuspend(&adev->dev); + pm_runtime_put(&adev->dev); return 0; probe_err3: